Blue lava? A blood-red waterfall? The natural world is full of surprises. If you think you've finally figured out Mother Nature, think again.

Blue Lava

Blue Lava

The lava flowing from Indonesia's Kawah Ijen volcano is a typical searing red during the day, but at night it glows a spectacular blue—the result of pure sulfuric acid seeping out from inside. Kawah Ijen contains one of the world's largest acidic crater lakes, a one-kilometer-wide, turquoise-colored body of water with a pH that measures 0.5 (remember that the pH scale runs from 0 to 14, with 0 being the mostly acidic). The lake is also a working sulfur mine, with miners often extracting the toxic substance by light of the lava's eerie blue glow.

Green Blood and Bones

Green Blood and Bones

While not every genus of the snakelike lizards known as skinks oozes green, Prasinohaema virens (green-blooded skink) has green blood, bones, and mucosal tissue. Biologist Christopher Austin determined that these viridescent tones are the result of high concentrations of biliverdin, a bile pigment that often causes jaundice in humans as well as the greenish color in some bruises. Biliverdin is extremely toxic, so why doesn't it kill the skinks? Austin believes Prasinohaema may have evolved to tolerate biliverdin as a way to keep plasmodia, the parasites known to cause malaria, from infecting its blood.